telsonman

i'm wondering if i should port my gt40p's, or just leave them normal. how much will porting and polishing cost, and will it affect my mpg???

oachs83

Any iron GT40 head that came factory Ford needs porting. Polishing is a waste of money unless you are a hardcore drag or racer. I am not sure on the cost and MPG depends on youo and your heavy foot.

nitrous_bob

absolutely do some.....you can almost double the performance of the head for alittle bit

exhaust is where you need to concentrate, open them up and just have them clean up the intakes

should be about $200

but get an opinion on the porter too, he might think your valves are shrouded and can clean up the bowls a little.

don't get crazy, but do something to them

tinman

IMHO, if you are even concerned about fuel mileage, GT40 heads and porting are the wrong things to be thinking of......